Chemical evolution models have been introduced in cosmological simulations starting from the 90's [1]}, [2]}.
While early studies including chemical enrichment mainly focused on galaxies [1]}, [4]}, soon Smoothed-Particle Hydrodynamics (SPH) simulations of
large-scale structure and galaxy clusters started to include chemical evolution models as well [5]}, [6]}, [7]}.
Despite different level of complexity, already in the early implementations, the metal production associated to both SNIa and SNcc was included, and the metal content of the gas was taken into account in the cooling process [8]}, [9]}.
In [7]}, the contribution to chemical enrichment due to low- and intermediate-mass stars undergoing the AGB phase, as well as the treatment of metallicity-dependent stellar yields and mass-dependent stellar life-times were also included [11]}.
Starting from the initial models that focused on total metallicity or iron abundance, an increasing level of detail has been reached over the years, with modern simulations typically following the production and evolution of several metal species separately (e.g. oxygen, silicon, etc.).
Chemical enrichment models are typically based on three fundamental pillars: the initial mass function (IMF) [12]}, [13]}, [14]}, and mass-dependent stellar life-times [15]}, [16]}, [17]},  and metal yields , , [18]}, [19]}, [20]}.
In SPH simulations [21]}, in particular, chemical evolution models are coupled directly with the star formation model, where every stellar particle is representative of a simple stellar population (SSP), that is a population of stars all characterized by the same age and metallicity. The assumptions on the IMF and on the stellar yields are required to predict the amount of metals generated by each SSP and the time-scale on which different enrichment channels (primarily SNIa, SNcc and AGB stars) release the metal mass into the surrounding gas elements [22]}, [23]}.
